Propeller.



0. J. H. FLINDT.

' PBOPELLEB.

APPLICATION FILED MAY 6, 1909.

Patented Dee 5, 1911.

CARL JULIUS HOVARD IFLINDT, 0F COPENHAGEN, DENMARK.

PROPELLER.

Specification of Letters Patent.

Patented. Dec. 5, 1911.

Application filed May 5, 1909. Serial No. 494,172.

To all whom it may concern:

Be it lmown that I, CARL JULIUS HOVARD FLINDT, a subject of the King ofDenmark, and residing at Bredgade No 36, Copenhagen, Denmark, haveinvented a new and useful Improvement inPropellers; and I do herebydeclare the following to be a full, clear, and exact description of thesame.

This invention relates to propellers, and among the objects in view istoprovide a propeller consisting of two blades formed from a singlesheet of material said blades being so positioned in relation to eachother and shaped in such a way so as to produce an augmented advancingeffect in comparison with the propellers hitherto known.

The invention is clearly illustrated in the accompanying drawingwherein- Figure 1 shows the plane sheet of metal before being shaped asa propeller, Fig. 2 is a side view of the propeller, and Fig. 3 is afront view of the same. 7

The lane blade or sheet is, as will be seen from Fig. 1 essentiallycircular, in which the cuttings shown are made so as to form two wings;the circular cutting 1 for the boss is arranged eccentrically and thetwo wings 2 and 3 meet at an acute angle 4. The two wings are thenessentially formed as two intersecting helical surfaces. 2 and 3indicate the forward or leading edges of said helical surfaces whichedges 2' and 3 begin near the axis, while 2 and 3" indicate theremaining edges of said helical surfaces. The generatrix at the edges 2and 3 forms an acute angle with the axis of the boss or propeller shaftbut this angle increases uniformly, i. e. becomes less and less acutetoward the edges 2 and 3". The generatrix is at the beginning a slightlycurved line, the concavity of which points in one direction; this lineis gradually turned into a straight line, then into a curved line withconcavity in the opposite direction. The blade thus formed will duringthe rotatingas distinct from the propellers hitherto knownofler theslightest possible resistance, and has a very considerablepressure-surface, and the pressure becomes even and uniform, goingessentially in the same direction as the vessel. Owing to the specialposition of the wings in relation to each other a double action upon thewater is obtained, as one half of the blade will further actuate thewater which has already been actuated by the other half, as also theshape of the blade prevents eddying of the Water, which is otherwisealways produced and incurs vibrations in the vessel. By the sameconsumption of power a greater speed and more steady course is thusobtained. Besides the said shape of the blade presents the advantagethat the blade cannot so easily be struck by timber, ropes or the likefloating in the water, such objects being by the evenly increasingpressure of the blade led away from the propeller.

Having thus described my invention, I claim as new and desire to secureby Letters Patent.

1. A propeller comprising two blades formed from a single sheet ofmaterial, each blade having a helical surface, the helical surfacesintersecting each other, and said blades being shaped to provide aneccentrically-located opening for a boss and a propeller shaft, and thegeneratrix at the leading edges of said helical surfaces forming anacute angle with the axis of said boss and the said angle increasinguniformly toward the other ends of the blades.

2. A propeller comprising two blades formed from a single sheet ofmaterial, each blade having a helical surface, the helical surfacesintersecting each other, and .said blades being so shaped as to providean eccentrically-located opening for a boss and a propeller shaft, andthe generatrix at the leading edges of said helical surfaces form ing anacute angle with the axis of said boss and the said angle increasinguniformly toward the other ends of the blades, the shape of each bladebeing such that the generatrix of its helical surface is at thebeginning a slightly curved line with the concavity pointing in onedirection and then a straight line and finally a curved line with theconcavity pointing in the opposite direction.

In testimony whereof, I have signed my name to this specification in thepresence of two subscribing witnesses.

CARL JULIUS HOVARD FLINDT.

Witnesses Vrcoo BLoM, G. Sruv.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. O.

